Handling GraphQL errors like a champ with unions and interfaces

GraphQL's robust type system, complemented by tools like the GraphQL Code Generator and typed JavaScript subsets such as TypeScript or Flow, enables rapid generation of fully typed data fetching code. Unlike traditional RESTful APIs, GraphQL allows for nullable fields and partial results, which can include an array of error objects when a resolver encounters an issue. Although initially challenging to reconcile with REST's status code error handling, GraphQL's approach to error management can be improved through the use of extensions that provide additional context. However, the lack of type safety in error codes can be addressed by leveraging GraphQL's union types and interfaces, allowing errors to be modeled as standard types with complex structures. This approach enhances type safety by using union types to differentiate between various error states within a schema, while interfaces abstract common fields across error types. This methodology also streamlines client-side error handling, as developers can handle errors more efficiently without needing constant updates to the client application, leveraging conventions and tools like the GraphQL Code Generator for improved workflow. Integrating these practices into GraphQL implementations can greatly enhance both server-side and client-side development experiences.